Sofa bed



FIG. 1 is a front perspective view of a sofa bed, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view, taken from the right of FIG. 2, the side opposite to that shown in FIG. 3 being the mirror image thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a view similar to FIG. 1, the sofa bed being in an unfolded position. 

The ornamental design for a sofa bed, as shown and described. 